Evaluation of Solar Pool Heating System Under Different Conditions

Heating water in outdoor pools is common, particularly in regions with cool or temperate climates. Several factors, including solar radiation, ambient air temperature, wind speed, and humidity, influence the pool water temperature. A key design challenge is to determine the collector surface area required to achieve the desired pool water temperature. In this study, a mathematical model was developed that accounts for the aforementioned factors. Under various operating conditions, thermal performance calculations were carried out. Climatic conditions at three locations across Europe, representing different climate regimes, were analyzed. The model was validated through comparison with results obtained in the POLYSUN simulation software. The calculations demonstrated that wind speed above the water surface has a significant impact on heat losses and, consequently, on water temperature. It causes both convective and evaporative heat losses. Locating the pool in a sheltered area results in a consistent reduction in heat losses. It was determined that, under the climatic conditions of Krakow, the installation of solar collectors with a surface area equal to 50 % of the pool surface enables the maintenance of daytime water temperatures above 21 °C for approximately 100 days. In the absence of solar collectors, achieving such temperatures is not feasible.